Merge remote-tracking branch 'origin/rotate_sll_improve' into rotate_sll_improve

Author: Hardvan

DIRECTORY.md

@@ -571,6 +571,7 @@
             * [UnionFind](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/searches/UnionFind.java)
             * [UpperBound](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/searches/UpperBound.java)
           * slidingwindow
+            * [LongestSubstringWithoutRepeatingCharacters](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/slidingwindow/LongestSubstringWithoutRepeatingCharacters.java)
             * [MaxSumKSizeSubarray](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/slidingwindow/MaxSumKSizeSubarray.java)
           * sorts
             * [AdaptiveMergeSort](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/AdaptiveMergeSort.java)
@@ -1163,6 +1164,7 @@
             * [UnionFindTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/UnionFindTest.java)
             * [UpperBoundTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/UpperBoundTest.java)
           * slidingwindow
+            * [LongestSubstringWithoutRepeatingCharactersTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/slidingwindow/LongestSubstringWithoutRepeatingCharactersTest.java)
             * [MaxSumKSizeSubarrayTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/slidingwindow/MaxSumKSizeSubarrayTest.java)
           * sorts
             * [AdaptiveMergeSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/AdaptiveMergeSortTest.java)